This invention relates to forming the lamp glass envelope for reflector type lamps on a ribbon machine wherein a novel mold construction is employed having three basic parts which cooperate in forming a bulb shape of generally parabolic contour and which terminates in a flattened face portion having light distributing elements formed on the exterior surface thereof.
The lamp glass envelopes customarily employed for reflector lamps such as
lamps and automotive headlamps are now formed by pressing separate reflector and lens parts in glass molds requiring not only relatively thick cross-sections for each part but further require that these parts by fusion sealed together during the lamp manufacture. Light distributing elements are located on the inner surface of the conventional lens members to shape the beam pattern of light emerging from the reflector surface which further requires an accurate registration with the conventional reflector members to do so effectively. A serious problem has long been recognized with said conventional pressed lamp constructions arising from the lack of proper registration when these separate lens and reflector members are fusion sealed together.
Accordingly, an important object of the present invention is to provide a lamp glass envelope for a reflector lamp having a unitary integral construction which includes the reflector and lens portions when said lamp glass envelope is initially formed.
Another important object of the present invention is to reduce the amount of glass customarily employed in the lamp glass envelope of a reflector lamp as well as significantly reduce the difficulties now encountered with lack of proper alignment between the lens and reflector portions in pressed type lamp constructions.
Still a further important object of the present invention is to provide an improved method for manufacture of said novel unitary lamp glass envelope on a ribbon machine by means of a novel mold design.